This invention was made with government support under Contract No.: DABT63-99-3-0002 awarded by the Department of the Army. The government therefore has certain rights in this invention.
The present invention relates to a conformal bearing assembly, and more particularly to a conformal bearing assembly having a resilient elastomeric member which compensates for tolerance variations between telescopic members.
A telescopic system often includes a bearing assembly between an outer telescopic member and an inner telescopic member. The outer telescopic member extends and retracts relative to the inner telescopic member upon the bearing assembly. Contact pressure is thereby developed between the bearing and the mating surface of the inner telescopic member. To provide effective relative translation between the inner and outer telescopic members, the inner telescopic member must be manufactured to provide a consistent uniform bearing mating surface.
Conformity of mating surface of the inner telescopic member directly influences the wear characteristics of the bearing. In some instances, the contact region between the bearing and the mating surface results in an interference condition. High pressures at the interference causes accelerated wear upon the bearing and mating surface which may result in an increase in the magnitude of force required to translate the telescopic members. Conversely, a clearance condition may exist between the bearing and the mating surface. High edge pressure upon the bearing may thereby be caused as the bearing transmits relative bending moment between the inner and outer telescopic member. Furthermore, the clearance may increase undesirable relative motion between the inner and outer telescopic members.
Accordingly, it is desirable to provide a conformal bearing assembly which compensates for tolerance variations between telescopic members.
The conformal bearing assembly according to the present invention includes a bearing housing, an elastomeric member and a bearing element. The bearing assembly is mounted between an inner and outer telescopic member. The bearing housing is preferably non-linear in cross-section which corresponds to the bearing surface of the adjacent telescopic member.
The elastomeric member allows the bearing element to substantially conform to the adjacent telescopic member irrespective of minor manufacturing inconsistencies along the adjacent telescopic member. Contact pressure between the bearing element and the adjacent telescopic member is thereby more evenly distributed which minimizes regions of interference and or clearance which may otherwise result in undesirable wear characteristics of the telescopic system.
In one embodiment, the conformal bearing assembly allows flapwise, edgewise, and other torsional moments to be transferable through the conformal bearing assembly and provides an additional degree of freedom for a variable diameter rotor blade assembly. The possibility of binding between the outboard rotor blade section and the torque tube is also thereby minimized while manufacturing tolerance envelopes of the telescopic members are increased.